According to the official announcement, "vape" was used by Rob Stepney in Why Do People Smoke?, written in 1983. Stepney wrote:

an inhaler or 'non-combustible' cigarette, looking much like the real thing, but...delivering a metered dose of nicotine vapour. (The new habit, if it catches on, would be known as vaping.)

The other nominees were:

bae n.used as a term of endearment for one's romantic partner.

budtender n.a person whose job is to serve customers in a cannabis dispensary or shop.

contactless adj.relating to or involving technologies that allow a smart card, mobile phone, etc. to contact wirelessly to an electronic reader, typically in order to make a payment.

indyref, n. an abbreviation of 'independence referendum', in reference to the referendum on Scottish independence, held in Scotland on 18 September 2014, in which voters were asked to answer yes or no to the question 'Should Scotland be an independent country?'

normcore n.a trend in which ordinary,unfashionable clothing is worn as a deliberate fashion statement.

slacktivism, n., informal actions performed via the Internet in support of a political or social cause but regarded as requiring little time or involvement, e.g. signing an online petition or joining a campaign group on a social media website; a blend of slacker and activism.